Amid all this talk circling overhead about the proposed expansion of Heathrow, I recently undertook the type of journey that environmental campaigners say is one of the key reasons why there is a call by some to expand capacity – lengthy trips within the UK.

Why on earth should we be encouraging even more flights between, say, Heathrow and Edinburgh (or Manchester, for that matter) when those passengers could be going by train in much the same time, when you make a fair city centre-to-city centre comparison?

I live in Cornwall and a big family bash was taking place at Shotley Bridge in County Durham. In order to attend, my family was going to have to travel about 430 miles (693km) each way – roughly the same distance as traveling from London to Lyon. We were, therefore, confronted with something of a conundrum: should we go by road, plane or train? (I’ve done some lengthy coach trips in my time, but I really didn’t relish that option.)

There were the usual financial and environmental cost implications to consider, but we had a wildcard to throw into the mix – our young children.

In environmental terms, the answer was easy. Get the train. But when we did the costings, getting the train would be almost twice as expensive as driving – nearly £200 (including the cost of a family rail card and tube journey across London) compared to about £100 spent at a garage forecourt.

To our great surprise, though, the cost of flying (Newquay-Newcastle, or Exeter to Newcastle) would have worked out at about £400 all in for the days we needed to travel, even if we had booked a couple of months in advance. We had assumed it would have at least beaten the cost of going by train.

To be honest, I was relieved that it turned out to be so expensive as I didn’t fancy facing pressure from my family to grab a domestic flight to avoid the hassle of taking the kids on either a long train or long car journey. It was also refreshing for once to see that the most environmentally unfriendly option was also the most expensive, which, to be honest, is the only way you are going to convince most people to take fewer flights.

So in the end it came down to a toss up between whether it would mean spending eight-odd hours on the train with the kids (somewhat counterintuitively, it was quicker to go via a change in London than on a direct, cross country train via Birmingham), or broadly the same time – if the going was good – in the car. After much debate, the prospect of allowing our young kids the chance to stretch their legs (but hopefully not their lungs) on the train won the day.

The trip itself proved to be fairly incident free and we made it there and back without delay. We even managed to somehow avoid the wrath of our fellow passengers after finding out we had been placed in the so-called quiet carriage for one of the legs. (Oh, how we longed, though, for one of those enclosed children’s play areas you find on some trains in Germany, France and other parent friendly nations.)

But there was no denying that by avoiding the plane on this particular route we had to make a considerable time sacrifice. After all, going by plane would have taken us about four hours door-to-door when you factor in getting to and from airports and the check-in time.

Some within the anti-airport expansion debate say that domestic flights cannot be justified and should be banned altogether. Personally, I think that the extremities of the British Isles are always going to put forward a fair case that they need to be served by a local airport (ironically, Newquay Airport is currently closed for three weeks due to an air traffic control cock-up meaning that my family would have been stuffed if we had flown out from there), but I do agree that it is insane that it is still often far cheaper to go by plane than by train for many of the workhorse domestic routes within Britain.

In this instance, though, I was more than happy to have allowed the train to take the strain. And being a First Great Western regular, I was gobsmacked to find free Wifi in all carriages on the National Express East Coast route between London King’s Cross and Newcastle. I’m sure there are horror stories to be told of travelling this route, but it was like a hallowed vision of what a train service could be like in the hopefully not-too-distant future.